# -*- coding: utf-8 -*-

"""
 (c) 2014-2016 - Copyright Red Hat Inc

 Authors:
   Pierre-Yves Chibon <pingou@pingoured.fr>

pagure notifications.
"""
from __future__ import print_function


# pylint: disable=too-many-branches
# pylint: disable=too-many-arguments


import datetime
import hashlib
import json
import re
import smtplib
import time
import warnings

import flask
import pagure

from email.mime.text import MIMEText
from six.moves.urllib_parse import urljoin


REPLY_MSG = 'To reply, visit the link below'
if pagure.APP.config['EVENTSOURCE_SOURCE']:
    REPLY_MSG += ' or just reply to this email'


def fedmsg_publish(*args, **kwargs):  # pragma: no cover
    ''' Try to publish a message on the fedmsg bus. '''
    # We catch Exception if we want :-p
    # pylint: disable=broad-except
    # Ignore message about fedmsg import
    # pylint: disable=import-error
    kwargs['modname'] = 'pagure'
    try:
        import fedmsg
        fedmsg.publish(*args, **kwargs)
    except Exception as err:
        warnings.warn(str(err))


def log(project, topic, msg, redis=None):
    ''' This is the place where we send notifications to user about actions
    occuring in pagure.
    '''
    # Send fedmsg notification (if fedmsg is there and set-up)
    if not project or project.settings.get('fedmsg_notifications', True):
        fedmsg_publish(topic, msg)

    if redis and project:
        redis.publish(
            'pagure.hook',
            json.dumps({
                'project': project.fullname,
                'topic': topic,
                'msg': msg,
            }))


def _add_mentioned_users(emails, comment):
    ''' Check the comment to see if an user is mentioned in it and if
    so add this user to the list of people to notify.
    '''
    mentio_re = r'@(\w+)'
    for username in re.findall(mentio_re, comment):
        user = pagure.lib.search_user(pagure.SESSION, username=username)
        if user:
            emails.add(user.default_email)
    return emails


def _clean_emails(emails, user):
    ''' Remove the email of the user doing the action if it is in the list.

    This avoids receiving emails about action you do.
    '''
    # Remove the user doing the action from the list of person to email
    if user and user.emails:
        for email in user.emails:
            if email.email in emails:
                emails.remove(email.email)
    return emails


def _get_emails_for_issue(issue):
    ''' Return the list of emails to send notification to when notifying
    about the specified issue.
    '''
    emails = set()
    # Add project creator/owner
    if issue.project.user.default_email:
        emails.add(issue.project.user.default_email)

    # Add project maintainers
    for user in issue.project.users:
        if user.default_email:
            emails.add(user.default_email)

    # Add people in groups with commits access to the project:
    for group in issue.project.groups:
        if group.creator.default_email:
            emails.add(group.creator.default_email)
        for user in group.users:
            if user.default_email:
                emails.add(user.default_email)

    # Add people that commented on the ticket
    for comment in issue.comments:
        if comment.user.default_email:
            emails.add(comment.user.default_email)

    # Add the person that opened the issue
    if issue.user.default_email:
        emails.add(issue.user.default_email)

    # Add the person assigned to the ticket
    if issue.assignee and issue.assignee.default_email:
        emails.add(issue.assignee.default_email)

    # Add the person watching this project, if the issue is public
    if issue.isa == 'issue' and not issue.private:
        for watcher in issue.project.watchers:
            emails.add(watcher.user.default_email)

    # Add public notifications to lists/users set project-wide
    if issue.isa == 'issue' and not issue.private:
        for notifs in issue.project.notifications.get('issues', []):
            emails.add(notifs)
    elif issue.isa == 'pull-request':
        for notifs in issue.project.notifications.get('requests', []):
            emails.add(notifs)

    # Remove the person list in unwatch
    for unwatcher in issue.project.unwatchers:
        if unwatcher.user.default_email in emails:
            emails.remove(unwatcher.user.default_email)

    # Drop the email used by pagure when sending
    emails = _clean_emails(
        emails, pagure.APP.config.get(pagure.APP.config.get(
            'FROM_EMAIL', 'pagure@fedoraproject.org'))
    )

    return emails


def _build_url(*args):
    ''' Build a URL from a given list of arguments. '''
    items = []
    for idx, arg in enumerate(args):
        arg = str(arg)
        if arg.startswith('/'):
            arg = arg[1:]
        if arg.endswith('/') and not idx + 1 == len(args):
            arg = arg[:-1]
        items.append(arg)

    return '/'.join(items)


def send_email(text, subject, to_mail,
               mail_id=None, in_reply_to=None,
               project_name=None):  # pragma: no cover
    ''' Send an email with the specified information.

    :arg text: the content of the email to send
    :arg subject: the subject of the email
    :arg to_mail: a string representing a list of recipient separated by a
        coma
    :kwarg mail_id: if defined, the header `mail-id` is set with this value
    :kwarg in_reply_to: if defined, the header `In-Reply-To` is set with
        this value
    :kwarg project_name: if defined, the name of the project

    '''
    if not to_mail:
        return

    if not pagure.APP.config.get('EMAIL_SEND', True):
        print('******EMAIL******')
        print('To: %s' % to_mail)
        print('Subject: %s' % subject)
        print('in_reply_to: %s' % in_reply_to)
        print('mail_id: %s' % mail_id)
        print('Contents:')
        print(text.encode('utf-8'))
        print('*****/EMAIL******')
        return

    if project_name is not None:
        subject_tag = project_name
    else:
        subject_tag = 'Pagure'

    if pagure.APP.config['SMTP_SSL']:
        smtp = smtplib.SMTP_SSL(
            pagure.APP.config['SMTP_SERVER'], pagure.APP.config['SMTP_PORT'])
    else:
        smtp = smtplib.SMTP(
            pagure.APP.config['SMTP_SERVER'], pagure.APP.config['SMTP_PORT'])

    for mailto in to_mail.split(','):
        msg = MIMEText(text.encode('utf-8'), 'plain', 'utf-8')
        msg['Subject'] = '[%s] %s' % (subject_tag, subject)
        from_email = pagure.APP.config.get(
            'FROM_EMAIL', 'pagure@fedoraproject.org')
        msg['From'] = from_email

        if mail_id:
            msg['mail-id'] = mail_id
            msg['Message-Id'] = '<%s>' % mail_id

        if in_reply_to:
            msg['In-Reply-To'] = '<%s>' % in_reply_to

        msg['X-pagure'] = pagure.APP.config['APP_URL']
        if project_name is not None:
            msg['X-pagure-project'] = project_name

        # Send the message via our own SMTP server, but don't include the
        # envelope header.
        msg['To'] = mailto
        salt = pagure.APP.config.get('SALT_EMAIL')
        mhash = hashlib.sha512('<%s>%s%s' % (mail_id, salt, mailto))
        msg['Reply-To'] = 'reply+%s@%s' % (
            mhash.hexdigest(),
            pagure.APP.config['DOMAIN_EMAIL_NOTIFICATIONS'])
        msg['Mail-Followup-To'] = msg['Reply-To']
        try:
            if pagure.APP.config['SMTP_USERNAME'] \
                    and pagure.APP.config['SMTP_PASSWORD']:
                smtp.login(
                    pagure.APP.config['SMTP_USERNAME'],
                    pagure.APP.config['SMTP_PASSWORD']
                )

            smtp.sendmail(
                from_email,
                [mailto],
                msg.as_string())
        except smtplib.SMTPException as err:
            pagure.LOG.exception(err)
    smtp.quit()
    return msg


def notify_new_comment(comment, user=None):
    ''' Notify the people following an issue that a new comment was added
    to the issue.
    '''

    text = u"""
%s added a new comment to an issue you are following:
``
%s
``

%s
%s
""" % (comment.user.user,
       comment.comment,
       REPLY_MSG,
       _build_url(
           pagure.APP.config['APP_URL'],
           comment.issue.project.name,
           'issue',
           comment.issue.id))
    mail_to = _get_emails_for_issue(comment.issue)
    if comment.user and comment.user.default_email:
        mail_to.add(comment.user.default_email)

    mail_to = _add_mentioned_users(mail_to, comment.comment)
    mail_to = _clean_emails(mail_to, user)

    send_email(
        text,
        'Issue #%s `%s`' % (comment.issue.id, comment.issue.title),
        ','.join(mail_to),
        mail_id=comment.mail_id,
        in_reply_to=comment.issue.mail_id,
        project_name=comment.issue.project.name,
    )


def notify_new_issue(issue, user=None):
    ''' Notify the people following a project that a new issue was added
    to it.
    '''
    text = u"""
%s reported a new issue against the project: `%s` that you are following:
``
%s
``

%s
%s
""" % (issue.user.user,
       issue.project.name,
       issue.content,
       REPLY_MSG,
       _build_url(
           pagure.APP.config['APP_URL'],
           issue.project.name,
           'issue',
           issue.id))
    mail_to = _get_emails_for_issue(issue)
    mail_to = _add_mentioned_users(mail_to, issue.content)
    mail_to = _clean_emails(mail_to, user)

    send_email(
        text,
        'Issue #%s `%s`' % (issue.id, issue.title),
        ','.join(mail_to),
        mail_id=issue.mail_id,
        project_name=issue.project.name,
    )


def notify_assigned_issue(issue, new_assignee, user):
    ''' Notify the people following an issue that the assignee changed.
    '''
    action = 'reset'
    if new_assignee:
        action = 'assigned to `%s`' % new_assignee.user
    text = u"""
The issue: `%s` of project: `%s` has been %s by %s.

%s
""" % (issue.title,
       issue.project.name,
       action,
       user.username,
       _build_url(
           pagure.APP.config['APP_URL'],
           issue.project.name,
           'issue',
           issue.id))
    mail_to = _get_emails_for_issue(issue)
    if new_assignee and new_assignee.default_email:
        mail_to.add(new_assignee.default_email)

    mail_to = _clean_emails(mail_to, user)

    uid = time.mktime(datetime.datetime.now().timetuple())
    send_email(
        text,
        'Issue #%s `%s`' % (issue.id, issue.title),
        ','.join(mail_to),
        mail_id='%s/assigned/%s' % (issue.mail_id, uid),
        in_reply_to=issue.mail_id,
        project_name=issue.project.name,
    )


def notify_assigned_request(request, new_assignee, user):
    ''' Notify the people following a pull-request that the assignee changed.
    '''
    action = 'reset'
    if new_assignee:
        action = 'assigned to `%s`' % new_assignee.user
    text = u"""
The pull-request: `%s` of project: `%s` has been %s by %s.

%s
""" % (request.title,
       request.project.name,
       action,
       user.username,
       _build_url(
           pagure.APP.config['APP_URL'],
           request.project.name,
           'pull-request',
           request.id))
    mail_to = _get_emails_for_issue(request)
    if new_assignee and new_assignee.default_email:
        mail_to.add(new_assignee.default_email)

    mail_to = _clean_emails(mail_to, user)

    uid = time.mktime(datetime.datetime.now().timetuple())
    send_email(
        text,
        'PR #%s `%s`' % (request.id, request.title),
        ','.join(mail_to),
        mail_id='%s/assigned/%s' % (request.mail_id, uid),
        in_reply_to=request.mail_id,
        project_name=request.project.name,
    )


def notify_new_pull_request(request):
    ''' Notify the people following a project that a new pull-request was
    added to it.
    '''
    text = u"""
%s opened a new pull-request against the project: `%s` that you are following:
``
%s
``

%s
%s
""" % (request.user.user,
       request.project.name,
       request.title,
       REPLY_MSG,
       _build_url(
           pagure.APP.config['APP_URL'],
           request.project.name,
           'pull-request',
           request.id))
    mail_to = _get_emails_for_issue(request)

    send_email(
        text,
        'PR #%s `%s`' % (request.id, request.title),
        ','.join(mail_to),
        mail_id=request.mail_id,
        project_name=request.project.name,
    )


def notify_merge_pull_request(request, user):
    ''' Notify the people following a project that a pull-request was merged
    in it.
    '''
    text = u"""
%s merged a pull-request against the project: `%s` that you are following.

Merged pull-request:

``
%s
``

%s
""" % (user.username,
       request.project.name,
       request.title,
       _build_url(
           pagure.APP.config['APP_URL'],
           request.project.name,
           'pull-request',
           request.id))
    mail_to = _get_emails_for_issue(request)

    uid = time.mktime(datetime.datetime.now().timetuple())
    send_email(
        text,
        'PR #%s `%s`' % (request.id, request.title),
        ','.join(mail_to),
        mail_id='%s/close/%s' % (request.mail_id, uid),
        in_reply_to=request.mail_id,
        project_name=request.project.name,
    )


def notify_cancelled_pull_request(request, user):
    ''' Notify the people following a project that a pull-request was
    cancelled in it.
    '''
    text = u"""
%s canceled a pull-request against the project: `%s` that you are following.

Cancelled pull-request:

``
%s
``

%s
""" % (user.username,
       request.project.name,
       request.title,
       _build_url(
           pagure.APP.config['APP_URL'],
           request.project.name,
           'pull-request',
           request.id))
    mail_to = _get_emails_for_issue(request)

    uid = time.mktime(datetime.datetime.now().timetuple())
    send_email(
        text,
        'PR #%s `%s`' % (request.id, request.title),
        ','.join(mail_to),
        mail_id='%s/close/%s' % (request.mail_id, uid),
        in_reply_to=request.mail_id,
        project_name=request.project.name,
    )


def notify_pull_request_comment(comment, user):
    ''' Notify the people following a pull-request that a new comment was
    added to it.
    '''
    text = u"""
%s commented on the pull-request: `%s` that you are following:
``
%s
``

%s
%s
""" % (comment.user.user,
       comment.pull_request.title,
       comment.comment,
       REPLY_MSG,
       _build_url(
           pagure.APP.config['APP_URL'],
           comment.pull_request.project.name,
           'pull-request',
           comment.pull_request.id))
    mail_to = _get_emails_for_issue(comment.pull_request)
    mail_to = _add_mentioned_users(mail_to, comment.comment)
    mail_to = _clean_emails(mail_to, user)

    send_email(
        text,
        'PR #%s `%s`' % (comment.pull_request.id, comment.pull_request.title),
        ','.join(mail_to),
        mail_id=comment.mail_id,
        in_reply_to=comment.pull_request.mail_id,
        project_name=comment.pull_request.project.name,
    )


def notify_new_email(email, user):
    ''' Ask the user to confirm to the email belong to them.
    '''

    root_url = pagure.APP.config.get('APP_URL', flask.request.url_root)

    url = urljoin(
        root_url or flask.request.url_root,
        flask.url_for('confirm_email', token=email.token),
    )

    text = u"""Dear %(username)s,

You have registered a new email on pagure at %(root_url)s.

To finish your validate this registration, please click on the following
link or copy/paste it in your browser, this link will remain valid only 2 days:
  %(url)s

The email will not be activated until you finish this step.

Sincerely,
Your pagure admin.
""" % ({'username': user.username, 'url': url, 'root_url': root_url})

    send_email(
        text,
        'Confirm new email',
        email.email,
    )
